<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div id="app">

        <input type="text" >
        <span>+</span>
        <input type="text" >
        <span>=</span>
        <span>结果</span>

        <!-- 拿到值的时候自动去掉首尾空格 -->
        <input type="text" >

        <hr>

        <input type="text" >
        <p>{{ msg2 }}</p>
    </div>

    <script src="./vue.js"></script>
    <script>
        new Vue({
            el: '#app',
            data() {
                return {
                    num1: 0,
                    num2: 0,
                    msg: '',
                    msg2: ''
                }
            },
        })
    </script>
</body>
</html>